What are the qualifications for becoming an eternal family according to LDS teaching?

I understand the LDS Church teaches the concept of an eternal family. I guess the husband and wife have to have been sealed for eternity in a Temple marriage, and, therefore, have to hold Temple recommends. I'm wondering if their earthly children also have to be Temple-worthy and if there are any other qualifications. If one child is not Temple-worthy, then I'm wondering if that child is not a part of the eternal family in the afterlife, but perhaps would still have some relationship with his/her siblings and parents and possibly Temple-worthy children. So, perhaps let us focus in on the specific qualifications for having an eternal family in heaven.